A stand alone, independent, and portable global positioning satellite (GPS) receiving device generates position location data when it is turned on and operational.
Mobile stations, such as cellular telephones, may generate position location data, either alone, via an integrated GPS receiver, and/or in combination with a communication system (e.g., a cellular telephone system) when the mobile station is turned on and operational.
Some external devices have position location functions that use or require position location data, but do not have an integral position location device, such as a GPS receiver. Such external devices may be connected to a stand alone, independent, portable GPS receiving device to receive the position location data when the GPS receiving device is turned on and operational. Since the primary function of the GPS receiving device primarily is to determine and generate position location data, the GPS receiving device is turned on when the external device needs or requires the position location data, and the GPS receiving device is turned off when the external device does not need or require the position location data. Turning on and off (e.g., manually) the GPS receiving device conserves resources, such as the portable power supply, processing, memory, network usage, etc.
Some position location devices or functions, which are internal to, integrated with, and embedded in a mobile station, receive position location data from the mobile station in response to an internally generated trigger or request, such as via an application program interface (API). Such a trigger conserves resources, such as the portable power supply, processing, memory, network usage, etc. with the mobile station. Such a trigger is practical and reasonable to implement in the mobile station, since the internal position location device and the mobile station are designed to work together and are designed at the same time.
Connecting external devices, having position location devices or functions, to a mobile station, having the ability to generate position location data, presents an undesirable engineering tradeoff. When an external device is connected to a mobile station, the mobile station does not know when to start and/or stop generating the position location data. For example, when the mobile station is turned on and operational to generate the position location data for the position location devices or functions in the external device, valuable resources may be unnecessarily consumed, if such position location devices or functions do not immediately or regularly need or require the position location data. Further, unnecessarily consuming the mobile station's resources has a detrimental effect on other functions in the mobile station that rely on the same resources. For example, unnecessarily generating position location data that are not used by the external device drains the mobile station's battery, which in turn reduces the mobile station's talk time or standby time.
Alternatively, if the mobile station is turned on and off, like the stand alone, independent, portable GPS receiving device described above, to conserve the mobile stations resources, then other desirable functions of the mobile station are not available to be used when the mobile station is turned off. For example, the mobile station cannot remain in standby mode, waiting for an incoming call, when the mobile station is turned off.
Therefore, there is a need for a method and an apparatus to automatically start and/or stop the generation of position location data for position location functions in external devices, which are adapted to be electrically coupled to and electrically decoupled from a mobile station.